Authentication Bypass in github.com/authelia/authelia/v4 (CVE-2021-32637)
Summary
Authentication bypass in github.com/authelia/authelia/v4 (CVE-2021-32637). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 4.29.3 or later.
Original description
The description as published by the source.
Authelia is a a single sign-on multi-factor portal for web apps. This affects uses who are using nginx ngx_http_auth_request_module with Authelia, it allows a malicious individual who crafts a malformed HTTP request to bypass the authentication mechanism. It additionally could theoretically affect other proxy servers, but all of the ones we officially support except nginx do not allow malformed URI paths. The problem is rectified entirely in v4.29.3. As this patch is relatively straightforward we can back port this to any version upon request. Alternatively we are supplying a git patch to 4.25.1 which should be relatively straightforward to apply to any version, the git patches for specific versions can be found in the references. The most relevant workaround is upgrading. You can also add a block which fails requests that contains a malformed URI in the internal location block.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2021-32637 has been found in github.com/authelia/authelia/v4.
Successful exploitation can lead to full system takeover.
What to do: upgrade github.com/authelia/authelia/v4 to 4.29.3 or later.
If unsure, ask your IT team or search "github.com/authelia/authelia/v4 CVE-2021-32637" on the vendor's site.
CVE-2021-32637 (github.com/authelia/authelia/v4) — CWE-287
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 4.29.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Authentication bypass (CWE-287) exists in github.com/authelia/authelia/v4.
Check the vendor advisory for the affected versions of github.com/authelia/authelia/v4.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 4.29.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/authelia/authelia/v4' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'github.com/authelia/authelia/v4' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/authelia/authelia/v4を grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/authelia/authelia/v4 to 4.29.3ステージング環境で 4.29.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- patch github.com
- patch github.com